Metal deactivators as adhesion promotors for vulcanizable elastomers to metals

ABSTRACT

Adhesion of metals to vulcanizable elastomers is promoted by a process of incorporating into the elastomer a metal deactivator and then vulcanizing the elastomeric composition while it is in contact with the metal surface.

United States Patent [1 Cowell et al.

[451 Sept. 23, 1975 METAL DEACTIVA'TORS AS ADHESION PROMOTORS FOR VULCANIZABLE ELASTOMERS TO METALS [75] Inventors: George K. Cowell, Brunswick, Ohio;

David J. Cherry, Somers, N.Y.

[73] Assignee: Ciba-Geigy Corporation, Ardsley,

[22] Filed: Oct. 10, 1973 [21] Appl. No.: 404,972

[52] US. Cl. 260/791; 117/133; 156/1 10 A; 156/124; 156/327; l56/338;-260/79.5 R [51] Int. Cl. B2911 5/02 [58] Field of Search 260/459 NC, 79.5 R, 791; 156/110 A, 124, 338, 327; 117/133 [56] References Cited UNITED STATES PATENTS 2,018,645 10/1935 Williams et a1. 260/45) R Primary Examiner-Ronald W. Griffin Attorney, Agent, or FirmCharles W. Vanecek [57] ABSTRACT Adhesion of metals to vulcanizable elastomers is promoted by a process of incorporating into the elastomer a metal deactivator and then vulcanizing the elastomeric composition while it is in contact with the metal surface.

7 Claims, No Drawings DETAILED DESCRIPTION This invention relates to the bonding of vulcanizable elastomeric compositionsto metals.

In the production of rubber articles, such as, forexample, pneumatic tires, belts, conveyor belts provided with reinforcing metallic elements, tubes provided with reinforcing cords or wires, and, in general, in the production of all rubber articles in which rubber is reinforced with metal, it isnecessary to obtain between the metal and the elastomeric composition a strong and durable bond in order to ensure a good efficiency and a long life for the articles produced. 1

It hasnow been unexpectedly found that unusually good bonds are produced between vulcanizable elastomeric compositions and metals when there is added to the vulcanizable elastomeric composition a compound with metal deactivating activity, and the compositions are then vulcanized while in contact with the metal. Compounds of particular suitability within this broad definition are found to have at least two nitrogen atoms directly bonded to each other, the remaining valence requirements of each nitrogen atom being fulfilled through bonding to hydrogen or to an organic residue. l-Iydrazine derivatives are thus especially suitable compounds. It appears that the activity of these compounds in adhesion promotion may be attributable in great measure to the NN atoms. Since the organic residue seems to be of secondary importance, it is felt that this invention may embrace practically all --N N' containing compounds with metal deactivating efficiency regardless of the specific organic residues involved.

One class of metal deactivating compounds of this invention is represented by the generic formula wherein R and R independently of each other represent alkyl having from I to 17 carbon atoms, cyclohexyl, aralkyl which can be substituted by one or two alkyl groups having each from 1 to 4 carbon atoms and- /or a hydroxyl group, phenyl, chlorophenyl, dichlorophenyl, phenyl which can be substituted by one or two alkyl groups having each from 1 to 4 carbon atoms and- /or a hydroxyl group, alkylphenyl having from 7 to 14 carbon atoms, alkoxyphenyl having from 7 to 24 carbon atoms or naphthyl, X represents the direct bond, an alkylene radical having from 2 to 8 carbon atoms, a phenylene radical or a naphthylene radical, and n represents or 1.

The compounds of formula I are prepared according to procedures described in US. Pat. No. 3,734,885.

R and R, respectively, represent in Formula I, e.g., an alkyl group having from 1 to 17 carbon atoms, such as methyl, ethyl, propyl, butyl, pentyl, hexyl, isoheptyl, octyl, decyl, undecyl, dodecyl, tetradecyl, or heptadecyl; or an alkylphenyl group having from 7 to 14 carbon atoms such as, e.g., phenyl which is substituted by methyl, tert.-butyl or tert.-octyl groups; or analkoxyphenyl group having from 7 to 24 carbon atoms such as, e.g, phenyl which is substituted by methoxy,

O 0 ll ll propoxy, butoxy, hexoxy, octoxy, decyloxy, dodecyloxy, tetradecyloxy or octadecyloxy.

Examples'of aralkyl or phenyl radicals represented by R and R, respectively, which radicals can be substituted by one or two alkyl groups having each from I to 4 carbon atoms and/or a hydroxyl group are: the 4- hydroxy-2-phenylethyl, 4-hydroxyphenyl, 3-tert.-butyl- 4-hydroxy-B-phenylethyl, 3-methyl-4-hydroxyphenyl, 2-hydroxy-3,5-di-tert.-butyl-phenyl and 3,5-diisopropyl-4-hydroxy-B-phenylethyl radical, more especially, however, i the 3,5-di-tert.-butyl-4-hydroxy-B- phenylethyl and 3,5-di-tert.-butyl-4-hydroxyphenyl radical.

When X in Formula I represents an alkylene radical having from 2 to 8 carbon atoms, this can be, e.g., ethylene, propylene, butylene, pentylene, hexylene or octylene. X however can also represent a phenylene radical such as the 1,3- or l,4-phenylene radical, or a naphthylene radical such as the 2,6- or l,4-naphthylene radical.v

Preferred asymmetrical compounds of Formula I are those. wherein R and R independently of each other represent 'alkyl having from 1 to 17 carbon atoms, cyclohexyl, benzyl, 3,5-di-tert.-butyl-4-hydroxy-B- phenylethyl, 3,5-ditert.-butyl-4-hydroxyphenyl, phenyl, chlorophenyl, dichlorophenyl, alkylphenyl having 7 or 8 carbon atoms, alkoxyphenyl having 7 or 8 carbon atoms or naphthyl, and X represents the direct usable according to the invention are the compounds.

in which R and R are identical and each represents alkyl having from 1 to 17 carbon atoms, cyclohexyl, benzyl, hydroxy-B-phenylethyl or hydroxyphenyl disubstituted by alkyl having from 1 to 4 carbon atoms, phenyl, chlorophenyl, dichlorophenyl, alkylphenyl having from 7 to 12 carbon atoms, alkoxyphenyl having from 7 to 12 carbon atoms or naphthyl, and X representsan alkylene radical having from 2 to 8 carbon atoms.

A third preferred group of symmetrical compounds of Formula I are the compounds in which R and R are identical and each represents alkyl having from 2 to 17 carbon atoms, cyclohexyl, benzyl, hydroxy-B- phenylethyl or hydroxyphenyl di-substituted by alkyl having from 1 to 4 carbon atoms, phenyl, chlorophenyl, dichlorophenyl, alkylphenyl having from 7 to 14 carbon atoms, alkoxyphenyl having from 7 to 18 carbon atoms, or naphthyl, and X represents phenylene or naphthylene.

Illustrative of the compounds of Formula I usable in the present invention are the following compounds:

N, N-di-fpropionyloxalic acid dihydrazide N, N'-di-butyroyloxalic acid dihydrazide N, N'-di-pelargonyloxalic acid dihydrazide N,N-di-cyclohexanoyloxalic acid dihydrazide N,N-di-phenylacetylacetyloxalic acid dihydrazide N,N-di-benzoyloxalic acid dihydrazide N,N'-di-a-naphthoyloxalic acid dihydrazide In the foregoing Formula II compounds are preferred N,N-di-o-toluoyloxalic acid dihydrazide wherein the R substituents are relatively simple, for ex- N,N-di-pmethoxybenzoyloxalic acid dihydrazide ample, lower alkyl, lower alkoxy. The R groups may N,N-di-caproyloxalic acid dihydrazide also be halogen e.g., fluorine, chlorine, etc. Where N,N-di-capryloyloxalic acid dihydrazide 5 large, bulky substituents such as tertiary alkyl groups N,N'-di-acetylsuccinic acid dihydrazide occur, it is preferred not to have the same on adjacent N,N-di-acetyladipic acid dihydrazide carbon atoms of the aromatic ring. The R groups in N,Ndi-propionyladipic acid dihydrazide compounds of the Formula ll may be either primary, N,N-acetylsebacic acid dihydrazide secondary or tertiary alkyl or alkoxy groups, such as N,N-di-benzoylsebacic acid dihydrazide l0 propyl, isopropyl, propoxy, isopropoxy, butyl, isobutyl, N,N-di-B-naphthoylsebacic acid dihydrazide tert.butyl, butoxy, isobutoxy, tert.-butoxy, etc. N,N-di-propionylterephthalic acid dihydrazid The compounds of the Formula II at least in part, are N,N'-pelarg0nylterephthalic acid dihydrazide known. For example, the compound Of the Formula I N,N'-di-2-ethylhexanoylterephthalic acid dihydrais a known p n n i pr p r c r ing to id known methods as described in US. Pat. No. N,N-di-lauroylterephthalic acid dihydrazide 3,110,696- N,N' di stearoylterephthalic acid dihydrazide A third class of metal deactivating compounds of this N,N-di-p-(tert.-octyl)-benzoylterephthalic acid diinvention is represented y the generic formula hydrazide N,N'-di-p-(octoxy)-benzoylterephthalic acid dihydrazide N,N-di-tridecanoylterephthalic acid dihydrazide N,N-di-palmitoylterephthalic acid dihydrazide N,N-di-valeroylterephahtlic acid dihydrazide R N,N'-di-butyroylisophthalic acid dihydrazide T f N,N-di-pelargonylisophthalic acid dihydrazide CH=NN1IC N,N-di-cyclohexanoylisophthalic acid dihydrazide N,N'-di-2-chlorobenzoyloxalic acid dihydrazide N,N'-bis-2,4dichlorobenzoylsebacic acid dihydrazide N-benzoyl-N-butyroyloxalic acid dihydrazide N-benzoyl-N'-pelargonyloxalic acid dihydrazide y y y y in which each of R and R is hydrogen, alkyl, chloro,

oxalic acid dihydrazide, and phenyl or, taken together, benzo. N,N-bis-{3(3,S-di-tert.butyl4-hydroxyphenyl)- Particularly valuable compounds embraced by For- OH HO propionyl}-adipic acid dihydrazide. mula [V included compounds of the formula 0 HO m 2|/| T if I T -",)H CH=N=NCCNN=CH A second class of metal deactivating compounds of in which each of n and m is an integer from 0 to 20. this invention is represented by the generic formula Thus included are compounds of the following three formulae:

R9 R2 R8 OH HO 3 OH HO H o o H R, R v II II CO NH N=CH 4 H (H= NC-C-NN=(H w 6 R5 OH HO wherein R R R R R R R and R are each inde- Inky] H O O H pendently hydrogen, alkyl-, especially lower alkyl, e.g., I I alkyl methyl, ethyl, propyl, butyl, pentyl, hexyl-, alkoxy, especially lower alkoxy, e.g., methoxy, ethoxy, propoxy, 6O

butoxy, pentoxy, hexoxy-, or a phenyl group.

The preferred compound of the Formula II is N- OH HO salicylidene-N-salicylhydrazide of the Formula II] lkyl T fi Tl T 1 alkyl CH=NNCCNN=CH- OH HO Vlll Co-NH-N=CH llI alkyl alkyl By the term alkyl as used hereinis intended a branched or straight chained hydrocarbon containing from one to 20 carbon atoms.- Representative of such groups, without being limited thereby, are thus methyl, ethyl, propyl, t-butyl, pentyl, hexyl, octyl, t-octyl, decyl, tetradecyl, octadecyl, eicosyl and the like.

The compounds of Formula IV are prepared according to procedures described in US. Pat. No. 3,357,944.

Illustrative of the compounds of Formula IV usable in the present invention are the following compounds:

oxalo-bis-(2-hydroxy-benzylidene-hydrazide) oxalo-bis-(2-hydroxy-5-methylbenzylidenehydrazide) oxalo-bis-(2-hydroxy-5 -t-butylbenzylidenehydrazide) oxalo-bis-(2-hydroxy-3 ,6-dimethylbenzylidenehydrazide) oxalo-bis-(2-hydroxy-5-t-amylbenzylidenehydrazide) oxalo-bis-(2-hydroxy-3,5-di-t-butyl-benzylidenehydrazide) oxalo-bis-(2-hydroxy-5-phenylbenzylidenehydrazide) oxalo-bis-(2-hydroxy-5-chlorobenzylidenehydrazide) oxalo-bis-( 2-hydroxyl -naphthylidene-hydrazide. A fourth class of metal deactivating compounds of this invention is represent d by the generic formula:

wherein R is a lower alkyl group containing from 1 to 6 carbon atoms, R is hydrogen or a lower alkyl group containing from 1 to 6 carbon atoms, and R is hydrogen, an alkanoyl group containing 2 to 18 carbon atoms or a group represented by the formula HO C,,H,,.C-

and n is an integer from to 5.

Illustrative examples of lower alkyl groups that are substituted on the phenyl moiety are methyl, ethyl, propyl, isopropyl, butyl, t-butyl, hexyl and the like. The preferred groups are the tertiary alkyls. Illustrative examples of the higher alkyl groups are heptyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl and the like, both straight chain and branched chain.

The compounds of Formula IX are prepared according to procedures described in US. Pat. No. 3,660,438.

Illustrative of the compounds of Formula IX usable in the present invention are the following compounds:

B-(3,5-dit-butyl-4-hydroxyphenyl)pro'pionylhydrazide N,N'-bis-B-(3,5-di-t-butyl-4-hydroxyphenyl)-propionylhydrazine N-stearyl-N'-{B-(3,5-di-t-butyl-4-hydroxyphenyl)- propionyl} -hydrazine N- {B-(3-ethyl-4-t-butyl-4-hydroxyphenyl)- propionyl}-N-B-(3,5-di-t-butyl-4-hydroxyphenyl) propionyl-hydrazine in which R denotes hydrogen, alkyl with 1 to 8 carbon atoms, alkenyl with 3 or 4 carbon atoms cycloalkyl with 6 to 8 carbon atoms, aralkyl with 7 to 9 carbon atoms,

phenyl, chlorine, hydroxyl, alkoxy with l to 18 carbon atoms, acyloxy with 2 to 18 carbon atoms or acylamino with 2 to 18 carbon atoms, R denotes hydrogen, alkyl with l to 5 carbon atoms, alkenyl with 3 or 4 carbon atoms, cyclohexyl, aralkyl with 7 to 9 carbon atoms, chlorine or hydroxyl, R denotes alkyl with 2 to 21 carbon atoms, cyclohexyl or the radical m CH:). @1

m denotes O or I and n denotes 0 to 2, the difference n--m being not less than 0 if the OH group is in the 0- position to the (CH group, and wherein R denotes hydrogen, alkyl with l to 8 carbon atoms, alkenyl with 3 or 4 carbon atoms, cycloalkyl with 6 to 8 carbon atoms, aralkyl with-71o 9 carbon atoms, phenyl, chlorine, hydroxyl, alkoxy with I to 18 carbon atoms, acyloxy with 2 to 18-;carbon atoms or acylamino with 2 to 18 carbon atomsand R ifm is 1, denotes hydrogen, alkyl with l to 5 carbon atoms, alkenyl with or 4 carbon atoms, cyclohexyl, aralkyl with 7 to 9 carbon atoms, chlorine or hydroxyl, or R if m is 0, denotes hydrogen, alkyl with I to 8 carbon atoms, alkenyl with 3 or 4 carbon atoms, cycloalkyl with 6 to 8 carbon atoms, aralkyl with 7 to 9 carbon atoms, phenyl, chlorine, hydroxyl, alkoxy with 1 to 18 carbon atoms, acyloxy with 2 to 18 carbon atoms or acylamino with 2 to 18 carbon atoms.

Preferred compounds of the formula X are those in which R denotes hydrogen, hydroxyl, chlorine, alkyl with l to 8 carbon atoms, alkoxy with 1 to 18 carbon atoms or acetoxy, R denotes hydrogen, butyl or chlorine and R denotes alkyl with 3 to 17 carbon atoms, cyclohexyl or the radical wherein m is or I, n is O to 2 and the difference nm is not less than 0 if the OH group is in the o-position to the (CH2),, group, R is hydrogen, hydroxyl, chlorine, alkyl with l to 4 carbon atoms, or alkoxy with 1 to 16 carbon atoms and R is hydrogen, chlorine, alkyl with 1 to 4 carbon atoms, hexadecyloxy, acetylamino or o-hydroxybenzoylamino.

If R R,,,, R R and/or R represents alkyl groups, these can, within the indicated limits, be methyl, ethyl, propyl, isopropyl, butyl, sec -butyl, tert.- butyl, amyl, tert.-amyl, sec.-amyl, hexyl, isoheptyl, octyl, tert.-octyl, nonyl, dodecyl, tetradecyl, hexadecyl, octadecyl or eicosyl. If R R R and/or R are alkenyl groups, these can be allyl or butenyl.

R R and/or R can be cycloalkyl groups with 6 to 8 carbon atoms such as, for example, cyclohexyl, a-methylcyclohexyl or cyclooctyl. If R R R and- /or R are aralkyl groups, they can be benzyl or oz-phenylethyl.

If R R and/or R is an alkoxy group with l to 18 carbon atoms this can be, for example, methoxy, ethoxy, propoxy, butoxy, hexoxy, octoxy, decyloxy, dodecyloxy, tetradecyloxy, or octadecyloxy. R R and/or R can also be an acyloxy group with 2 to 18 carbon atoms or an acylamino group with 2 to 18 carbon atoms, acyl being for example, an acyl radical of the following acids: acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, caproic acid, 2- ethylcaproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, acrylic acid, methacrylic acid, crotonic acid, oleic acid, benzoic acid, phenylacetic acid and salicyclic acid.

Compounds of the formula X which are particularly preferred are those in which R denotes hydrogen, alkyl with 1 to 8 carbon atoms, chlorine or alkoxy with l to 8 carbon atoms, R denotes hydrogen, alkyl with l to 5 carbon atoms or chlorine and R denotes alkyl with 3 to 17 carbon atoms, cyclohexyl, benzyl or one of the radicals wherein n denotes 0 to 2, R and R independently of one another denote hydrogen, alkyl with l to 8 carbon atoms, chlorine or alkoxy with l to 8 carbon atoms, and R and R independently of one another denote hydrogen, alkyl with l to 5 carbon atoms or chlorine.

The compounds of Formula X are prepared according to procedures described in US. patent application Ser. No. 256,969, filed May 25, 1972.

Illustrative of the compounds of Formula X usable in the present invention are the following compounds:

in which R denotes hydrogen, alkyl with l to 8 carbor atoms, alkoxy with 1 to 18 carbon atoms, unsubstitutec phenyl, phenyl substituted by lower alkyl groups, lowei alkoxy groups, halogen and/or hydroxyl groups, the

group or the group R and R independently of one another denote hydrogen, alkyl with l to 18 carbon atoms, cyclohexyl, benzyl, unsubstituted phenyl or phenyl substituted by 1 or 2 alkyl groups each having 1 to 8 carbon atoms, or R and R conjointly, with inclusion of the nitrogen atom, denote a saturated S-membered to 7-membered het'erocyclic ring, and the rings A are unsubstituted or 65 are substituted by l or 2 alkyl groups each having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms and/or 1-3 chlorine atoms.

In formula XI, R for example, denotes an alkyl group of 1 to 18 carbonatoms, such as methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl or octadecyl, an alkoxy group with l to 18 carbon atoms, such as methoxy, propoxy, butoxy, hexoxy, octoxy, decyloxy, dodecyloxy, hexadecyloxy or octadecyloxy, or a phenyl group which can be substituted by lower alkyl, such as methyl, ethyl, propyl or butyl, by lower alkoxy groups, such as methoxy, ethoxy, propoxy, or butoxy, by halogen, such as chlorine or bromine, and by a hydroxyl group, the latter preferably being in the ortho position. In the description, lower alkyl or alkoxy groups denote alkyl or alkoxy groups with l to 4 carbon atoms. R can be unsubstituted, monosubstituted or disubstituted amino group, wherein the substituent or substituents can be unbranched or branched alkyl with l to 18 carbon atoms for example methyl, ethyl, propyl, isopropyl, butyl, tert.-butyl, pentyl, hexyl, octyl, tert.-ctyl, decyl, dodecyl, tetradecyl, hexadecyl or octadecyl. If R is a phenyl substituted by l or 2 alkyl groups, the alkyl groups contain 1 to 8 carbon atoms and are, for example, methyl, ethyl, propyl, butyl, isobutyl, amyl, hexyl, octyl or isooctyl. R can also be a five-membered to seven-membered heterocyclic group containing nitrogen in the nucleus, which is bonded via a nitrogen atom to the triazine ring of the compound of the formula XI, for example the piperidine or the morpholine group. The nuclei A in the formula XI can be substituted, for example, by one or two identical or different alkyl groups of l to 18 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, tert.-butyl, pentyl, hexyl, octyl, text-octyl, decyl, dodecyl, tetradecyl, hexadecyl and octadecyl, or an alkoxy group with l to 18 carbon atoms, such as methoxy, propoxy, butoxy, hexoxy, decyloxy, dodecyloxy, hexadecyloxy, or octadecyloxy.

Preferred compounds of the formula XI are those in which R denotes an alkyl group with 1 to 3 carbon atoms, an alkoxy group with 2 to 4, especially 3 and 4, carbon atoms, or the group wherein R and R independently of one another are hydrogen, alkyl with 1 to 8 carbon atoms, cyclohexyl, benzyl, or phenyl, or R and R with inclusion of the nitrogen atom, form the radical of pyrrolidine, piperidine, morpholine or hexamethyleneimine, and R and R together contain 1 to 8 carbon atoms, and R and the substituents of A together contain at most 12 carbon atoms.

Compounds in which R and R independently of one another denote hydrogen, alkyl with 1 to 8 carbon atoms or phenyl, and R and R together contain 1 to 8 carbon atoms, are particularly preferred.

Particularly preferred compounds are those in which R denotes alkyl with l or 2 carbon atoms, alkoxy with 1 to 4'carbon atoms, unsubstituted phenyl, phenyl substituted by 1 r0 2 methyl groups, chlorine, methoxy or hydroxyl, the group v or the group rine, with R and the substituents of A together containing at least 13 carbon atoms.

The compounds of Formula Xl are prepared according to procedures described in U.S. patent application Ser. No. 150,757, filed June 7, 1971.

Illustrative of the compounds of Formula XI usable in the present invention are the following compounds:

2-(octadecylamino)-4,6-di-salicyloylhydrazino-striazine 2-(di-Z-ethylhexylamino)-4,6-bis-(2-hydroxy-5-tert.-

butylbenzoylhydrazino)-s-triazine 2-(dioctadecylamino-4,6-bis-(2-hydroxy-5-tert.-

octylbenzoyl-hydrazino)-s-triazine 2-dioctadecylamino-4,6-bis-(2-hydroxy-4- octoxybcnzoylhydrazino )-s-triazine 2-(di-2-ethylhexyl-amino)-4,6-bis-( 2-hydroxy-4- butoxybenzoylhydrazino)-s-triazine 2-(di-isopropylamino)-4,6-bis-(2-hydroxy-4-octoxybenzoylhydrazino)-s-triazine 2-propoxy-4,6-bis-(2-hydroxy-4-octoxybenzoylhyd razion )-s-triazine and compounds of the formula O N 1 a H OH L-hutyl C-hHNH N NHNH-C L-hutyl l.hut vl in which X denotes the radicals OH OH 24 XII in which R R R and R independently of one another denote hydrogen, alkyl with l to 18 carbon atoms, alkenyl with 3 to 4 carbon atoms, cycloalkyl with 6 to 8 carbon atoms, aralkyl with 7 to 9 carbon atoms, alkoxy groups with l to 18 carbon atoms, the latter preferably only as substituents R and R phenyl and chlorine, and R and R independently of one another can additionally also denote hydroxyl, acyloxy with 2 to 18 carbon atoms or acylamino with 2 to 18 carbon atoms,

In the formula XII, R R R and R for example denote an alkyl group with 1 to 18 carbon atoms, such as methyl, ethyl, propyl, butyl, sec.-butyl, tert.-butyl, n-amyl, sec.amyl, tert.-amyl, tert.-hexyl, isoheptyl, octyl, isooctyl, tert.-octyl, decyl, undecyl, dodecyl, tert.- dodecyl, tetradecyl or octadecyl, an alkenyl group with 3 to 4 carbon atoms, such as allyl, or butenyl, a cycloalkyl group with 6 to 8 carbon atoms, such as cyclohexyl, or cyclooctyl, an aralkyl group with 7 to 9 carbon atoms, such as benzyl, a-methylbenzyl or a,a-dimethylbenzyl or an alkoxy group with l to 18 carbon atoms, such as a methoxy, propoxy, butoxy, octoxy, decyloxy, dodecyloxy, tetradecyloxy or octadecyloxygroup.

The substituents R and R denoting acyloxy or acylamino groups with 2 to 18 carbon atoms can be acyl derivatives of carboxylic acids, such as, for example,

acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, caproix acid, 2-ethylcaproic acid, lauric acid, capric acid, myristic acid, palmitic acid, stearic acid, acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, oleic acid, benzoic acid and phenylacetic acid.

Amongst the compounds of the formula XII, those are preferred in which R R24, R and R indepen- V dently of one another denote hydrogen, alkyl groups with l to 12 carbon atoms, cycloalkyl groups with 6 or 7 carbon atoms, aralkyl groups with 8 or 9 carbon atoms, phenyl, and chlorine and R and R indepen dently of one another also denote hydroxyl, alkoxy groups with l to 12 carbon atoms, acyloxy groups with 2 to 18 carbon atoms and acylamino groups with 2 to 18 carbon atoms.

Amongst the compounds of the formula XII, those are particularly preferred in which R R R and R independently of one another denote hydrogen alkyl groups with l to 8 carbon atoms, cyclohexyl, a-methylbenzyl, a,a-dimethylbenzyl and chloride and R and R independently of one another also denote alkoxy groups with I to 12 carbon atoms, or those in which R and R independently of one another denote hydrogen, alkyl with I to 8 carbon atoms, alkoxy with l to 8 carbon atoms, phenyl, hydroxyl, chlorine, a-methylbenzyl, alkanyloxy with 2 to 18 carbon atoms, or alkanoylamino with 2 to 18 carbon atoms, R can also denote alkoxy with 9 to l7 carbon atoms and R and R independently of one another denote hydrogen tert.-butyl or methoxy.

The compounds of Formula XII are prepared according to procedures described in US. patent application Ser. No. 186,393, filed Oct. 4, 1971.

Illustrative of the compounds of Formula XII usable in the present invention are the following compounds:

N,N'-bis-salicyloyl-hydrazine N,N-bis-(2-hydroxy-5-tert.-butylbenzoyl)-hydrazine N,N'-bis-(2-hydroxy-5-tert.-octylbenzoyl)-hydrazine N,N'-bis-(2-hydroxy-3,5-di-tert.-butylbenzoyl)- hydrazine N,N-bis(2-hydroxy-5-methylbenzoyl)-hydrazine N,N'-bis-(2-hydroxy-5-chlorobenzoyl)-hydrazine N,N'-bis-(2-hydroxy-3,S-dichlorobenzoyl)-hydrazine N,N'-bis-(2-hydroxy-5-tert.-dodecylbenzoyl)- hydrazine N,N'-bis-(2-hydroxy-4,5-dimethylbenzoyl)- hydrazine N,N'-bis-(2-hydroxy-5-sec.-butylbenzoyl)-hydrazine N,N-bis-(2-hydroxy-5-sec.-octylbenzoyl)-hydrazine N,N'-bis-(2-hydroxy-5-sec.-nonylbenzoyl)-hydrazine N,N-bis-(2-hydroxy-5-cyclohexylbenzoyl)- hydrazine N,N'-bis-(2-hydroxy5-cyclooctylbenzoyl)-hydrazine N,N-bis-(Z-hydroxy-S-ot-methylbenzylbenzoyl)- hydrazine 4 N,N-bis-(2-hydroxy-4-methoxybenzoyl)-hydrazine N,N'-bis-(2-hydroxy-4-ethoxybenzoyl)-hydrazine N ,N '-bis(2-hydroxy-4-butoxybenzoyl )-hydrazine N ,N '-bis-( 2-hydroxy-4-dodecylbenzoyl )-hydrazine N,N-bis-(2-hydroxy-4-octadecyloxybenzoyl)- hydrazine N,N'-bis-(2-hydroxy-4-acetoxybenzoyl)-hydrazine N,N'-bis-(2-hydroxy-4-lauroylbenzoyl)-hydrazine N,N-bis-(2-hydroxy-4-stearoyloxybenzoyl)- hydrazine N,N-bis-(2-hydroxy-4-octoxybenzoyl)-hydrazine N,N'-bis-(2-hydroxy-5-octoxybenzoyl)-hydrazine N-(2-hydroxy-4-octoxybenzoyl)-N'-(2hydroxy-5 tert.-octylbenzoyl)-hydrazine N-(2-hydro xybenzoyl)-N'-(2-hydroxy-5- hexadecyloxybenzoyl)-hydrazine N-( 2 hydroxybenzoyl)-N-(2-hydroxy-5-stearyloxybenzoyl)-hydrazine N-( 2-hydroxybenzoyl)-N'-( 2-hydroxy-5butoxybenzoyl)-hydrazine N,N'-bis-(2-hydroxy-4-stearyloxybenzoyl)- hydrazine.

An eighth class of metal deactivating compounds of this invention is represented by the generic formula in which R and R independently of one another denote the unsubstituted phenyl group, a phenyl group substituted by a hydroxyl group in the mor pposition by one or two alkyl groups each with l to 4 carbon atoms, by one or two alkenyl groups each with 3 or 4 carbon atoms by one or two cycloalkyl groups each with 6 to 8 carbon atoms, by one or two chlorine atoms, by one or two alkoxy groups each with l to 18 carbon atoms, by one or two acyloxy groups each with 2 to 18 carbon atoms, by an acylamino group with 2 to 18 carbon atoms or by an amino group in the o-position, or a pyridyl radical or in which, if R denotes a substituted phenyl group, R also denotes hydrogen, alkyl with 1 to 18 carbon atoms, cyclohexyl or benzyl.

It has now been found that the compounds of the formula XIII in which R and R independently of one another denote the unsubstituted phenyl group, a phenyl group substituted by a hydroxyl group in the m or p-position, by one or two alkyl groups each with l to 4 carbon atoms, by one or two alkenyl groups each with 3 or 4 carbon atoms, by one or two cycloalkyl groups each with 6 8 carbon atoms, by one or two chlorine atoms, by one or two alkoxy groups each with l to 18 carbon atoms, by one or two acyloxy groups each with 2 to 18 carbon atoms, by an acylamino group with 2 to 18 carbon atoms or by an amino group in the o-position, or a pyridyl radical or in which if R denotes a substituted phenyl group, R also denotes hydrogen, alkyl with l to 18 carbon atoms, cyclohexyl or benzyl.

If R and R are phenyl groups substituted by alkyl groups with l to 4 carbon atoms each, the alkyl groups can be methyl, ethyl, propyl, iso-propyl, butyl, sec.butyl or tert.butyl. As alkenyl-substituted phenyl groups, R and R can, for example, be allylphenyl or butenylphenyl. If the substituents of the phenyl groups R and R are cyclohexyl groups each with 6 to 8 carbon atoms, these substituents can be cyclohexyl, a-methylcyclohexyl or cyclooctyl. If R and R denote phenyl groups substituted by alkoxy groups each with 1 to 8 carbon atoms, the alkoxy groups can be methoxy, ethoxy, propoxy, iso-propoxy, butoxy, sec.-butoxy, tert.- butoxy, pentoxy, tert.-pentoxy, pentoxy. hexoxy, isoheptoxy, octoxy or 1,1,3,3-tetramethylbutoxy, undecyloxy, dodecyloxy, hexadecyloxy, or octadecyloxy. R and R can also be phenyl radicals substituted by acyloxy or acylamino groups, each with 2 to 18 carbon atoms, in which case acyl" can be, for example, the acyl radical of the following acids; acetic acid, propionic acid, butyric acid, isobutyric acid, valcric acid, ca-

proic acid, Z-ethylcaproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, benzoic acid or phenylacetic acid. The preferred acyl radical is the radical of the benzoic acid. If R denotes a substituted phenyl groups, R can also be an alkyl group with l to 18 carbon atoms such as methyl, ethyl, propyl, butyl, pentyl, hexyl, iso-heptyl, octyl, no nyl, undecyl, dodecyl, tetradecyl, hexadecyl or octadecyl.

The preferred compounds of the formula XIII are those in which R and R independently of one another denote a phenyl group which is substituted by a hydroxyl group in the mor pposition, by one or two alkoxy groups each with 1 to 18, and particularly preferentially l to 16, carbon atoms, by an acylamino group with 2 to 7 carbon atoms, or by an amino group in the 0- position or in which, if R represents an acylaminophenyl group with 2 to 7 carbon atoms, in the acyl radical, R also denotes alkyl with l to 8 carbon atoms, and particularly preferentially methyl, benzyl or phenyl.

The compounds of Formula XIII are prepared according to procedures described in U.S. patent application Ser. No. 307,269, filed Nov. 16, 1972.

Illustrative of the compounds of Formula XIII usable in the present invention are the following compounds:

N,N-bis-(3,S-dimethoxybenzoyl)-hydrazine N,N-bis-(4-octyloxybenzoyl)-hydrazine N-( 4-benzoylaminobenzoyl )-N -benzoyl-hydrazine N-(4-acetylaminobenzoyl)-N'-acetyl-hydrazine 'N,N-bis-(2-aminobenzoyl)hydrazine.

A ninth class of metal deactivating compounds of this invention is represented by the generic formula in which X denotes a direct bond, an alkylene radical with l to 8 carbon atoms, a phenylene radical or a naphthylene radical and n denotes 0 or 1, and the rings A are unsubstituted or one ring A or both rings A are substituted by alkyl groups, alkenyl groups, cycloalkyl groups, aralkyl groups, further hydroxyl groups, alkoxy groups, acyloxy groups, acylamino groups, or halogen, preferably by l or 2 alkyl groups with l to 18 carbon atoms, 1 or 2 alkenyl groups with 3 to 4 carbon atoms, 1 or 2 cycloalkyl groups with 6 to 8 carbon atoms, 1 or 2 benzyl groups, I or 2 a-methylbenzyl groups, a fur ther hydroxyl group, an alkoxy group with 1 to 18 carbon atoms, an acyloxy group with 2 to 18 or an acylamino group with 2 to 18 carbon atoms, and l or 2 chlorine atoms.

X in the formula XIV can, for example, be an alkylene radical with l to 8 carbon atoms, such as methylene, ethylene, propylene, butylene, trimethylbutylene, pentylene, hexylene or octylene. It can also denote a phenylene radical, such as the 1,3- or 1,4-phenylene radical, or a naphthylene radical, such as the 2,6- or 1,4-naphthylene radical. The rings A can each be substituted by l or 2 alkyl groups with, preferably, 1 to 8 carbon atoms, such as, for example, methyl, ethyl, propyl, iso-propyl, butyl, sec-butyl, terti-butyl, amyl, tert.- amyl, sec-amyl, hexyl, iso-heptyl, octyl, te1't.-octyl, sec.-nonyl and dodecyl. The rings A can also each be substituted by l or 2 alkenyl groups with, preferably, 3

or 4 carbon atoms, such as, for example, allyl or butenyl, or 1 or 2 cycloalkyl groups with preferably 6 to 8 carbon atoms, such as, for example, cyclohexyl, a-methylcyclohexyl or cyclooctyl. If the substituent of the rings A is an alkoxy group with, preferably 1 to 18 carbon atoms, this group can, for example, be methoxy, ethoxy, propoxy, butoxy, hexoxy, octoxy, decyloxy, dodecyloxy, tetradecyloxy or octadecyloxy. The rings A can furthermore each be substituted by an acyloxy group, preferably with 2 to 18 carbon atoms, or an acylamino group, preferably with 2 to 18 carbon atoms and the acyl radicals of the following acids, for example, can be involved: acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, caproic acic, 2-ethylcaproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, acrylic acid, methacrylic acid, crotonic acid, oleic acid, benzoic acid and phenylacetic acid.

The compounds of the formula XIV in which X denotes the direct bond, an alkylene radical with 3 to 8 carbon atoms, a phenylene radical or a naphthylene radical and n denotes O or 1 and the rings A can be unsubstituted or each substituted by 1 or 2 alkyl groups with l to 8 carbon atoms, an alkoxy group with 1 to 18 carbon atoms or chlorine, are particularly preferred.

Those compounds of the formula XIV are particularly preferred, in which X denotes an alkylene radical with 3 to 8 carbon atoms and n denotes 0 or 1 and the rings A are unsubstituted or in which X denotes the direct bond and n denotes 1 and the rings A are each substituted by l or 2 alkyl groups with 1 to 8 carbon atoms, and/or an alkoxy group with 1 to 8 carbon atoms.

The compounds of Formula XIV are prepared according to procedures described in U.S. Pat. application Ser. No. 170,379, filed Aug. 9, 1971.

Illustrative of the compounds of Formula XIV usable in the present invention are the following compounds:

N,N'-bis-salicyloyl-oxalic acid dihydrazide N,N-bis-(2-hydroxy5-tert.butyl-benzoyl)-oxalic acid dihydrazide I N,N-bis-(2-hydroxy-4-octoxy-benzoyl)-oxalic dihydrazide N,N'-bis-salicyloyl-adipic acid dihydrazide N,N-bis-salicyloyl-sebacic acid dihydrazide N,N-bis-(2-hydroxy3,5-di-tert.butylbenzoyl)- adipic acid dihydrazide N,N-bis-(2-hydroxy-3,5di-tert.butyl-benzoyl)- terephthalic acid dihydrazide N,N-bis-(2-hydroxy5-tert.butyl-benzoyl)- terephthalic acid dihydrazide N,N-bis-(2-hydroxy-4-methoxybenzoyl)-sebacic acid dihydrazide N,N'-bis-(2-hydroxy-4-octoxybenzoyl)-oxalic dihydrazide vl' I,N-bis-(2-hydroxy-4-octoxybenzoyl)-sebacic acid dihydrazide N,N-bis-(2-hydroxy-3,5-di-tert.butyl-benzoyl)- oxalic acid dihydrazide N,N'-bis-(2-hydroxy-4-methoxybenzoyl)-oxalic acid dihydrazide N,N'-bis-(2-hydroxy-4-methoxy-benzoyl)- trimethyladipic acid dihydrazide.

A tenth class of metal deactivating compounds of this invention is represented by the generic formula acid acid

' merizable wherein R and R independently of one another are alkyl of from 1 to 17 carbon atoms. Compounds of Formula XV can be prepared by methods well known in the art.

In addition to the classes of compounds presented above, the N-N containing compounds disclosed in the following patents can also be employed as the adhesion promoting compound of the invention and the disclosures contained in these patents are incorporated herein.

U.S. Pat. No. 3,549,572

U.S. Pat. No. 3,673,152

U.S. Pat. No. 3,560,434

U.S. Pat. No. 3,629,189

German Offenlegungsschrift 2164234 German Offenlegungsschrift 2164635 German Offenlegungsschrift 1926547 German Offenlegungsschrift 1927447 According to the present invention therefore, there is provided a method of bonding a vulcanizable elastomeric composition to a metal surface during vulcanization which comprises adding to a vulcanizable elastomeric composition a metal deactivating compound as previously defined in an amount of from 0.05 phr to 10 phr by weight based on the weight of the elastomer, and preferably from 0.1 to 5.0 phr, and vulcanizing the composition while it is in contact with the metal surface to provide a strong and durable bond. There is further provided a product of the method described in this paragraph.

According to the present invention, there is also provided a composition which comprises vulcanizable elastomer, a vulcanizing agent, and a metal deactivating compound as previously defined in an amount of from 0.05 phr to 10 phr by weight based on the weight of the elastomer, and preferably from 0.10 to 5.0 phr.

The vulcanizable elastomeric composition may be produced by mixingthe ingredients of the composition in the normal manner in an internal mixer, for example, an extruder, a Banbury mixer and/or on a two-roll mill. After mixing, the composition may be applied to a metal surface and vulcanized. After application to the metal surface, the composition is normally vulcanized at a temperature of from C to C. The time of vulcanization may be varied according to the vulcanization temperature and the properties desired in the vulcanizate, as is known in the art.

The additives of this invention can be used with any vulcanizable elastomer. All natural and/or synthetic rubbers are usable in the present invention. Such elastomers include polydienes such as polybutadiene or polyisoprene, including natural rubber; copolymers of dienes such as butadiene or isoprene with other copolymonomers such as styrene, alphamethylstyrene, an acrylic ester, methylisopropenylketone, isobutylene, acrylonitrile or an unsaturated carboxylic acid; halogenated rubbers, such as polychloroprene or fluororubbers; interpolymers of one or more monolefins with a monomer which confers unsaturation on the interpolymer, for example, an unsaturated ethylene/propylene interpolymer such as an ethylene/- p ropylene/dicyclopentadiene terpolymer, sulphur-vulcanizable polyurethane rubbers; butyl rubber containing at least 0.8% unsaturation; and combinations of the above elastomers, e.g., natural rubber/butadienestyrene copolymer blends, a mixture of a saturated copolymer of ethylene and propylene with an unsaturated interpolymer of ethylene, propylene and a monomer comprising unsaturation in the interpolymer, etc.

In addition to the metal deactivating compounds previously defined,,the compositions of this invention may contain other conventional additives including accelerminutes of mixing, 1.00 part stearic acid plus 5.00 parts of tackifier (Piccovar 420) were added. After mixing 2 for an additional minute, 50.00 parts of carbon black (Continex FEF (N-550)) were added in two equal porators, activators, anti-cracking agents,'antioxidants, ani Th two portions were added after 1 and 2 hozohams anti-scorching agents antistatic agents minutes of total mixing time. Zinc oxide, 1.00 part, was Parsing agents, extruders fillers, intemal lubricants, added after 3.5 minutes of total mixing time and the plasticizers and Softeners, Processing aids, retardel's mix was swept down after 4.5 minutes of total mixing tacklfiel'sy Vulcanizlng agents Pigments, These time. After mixing for an additional 1.5 minutes to conventional ingredients and additives are added to the make a total of 6 minutes the entire mix was dumped elastomeric material in suitable amounts in known at a temperature of about manners to produce a vulcanizable composition based Sample preparation on the selected elastomer.

The vulcanizable compositions which may be bonded g ij fs tgzg gilzfgi sgs gggg i zzz gggs b the method of th resent invention will referabl c ntain carbon blacl fhe amount of carbori black in Ri z z j lg g g zg if i z f g ggg 2;. cluded will depend upon the desired nature of the prodsulfur, 075 part accelerator (SANTOCUliE 5 and since although the hardness is increased by 1.60 parts of the additive compound were added After creased amounts of carbon black, the resilience of the 7 minutes of mini the Stock was Sheeted rubber, when vulcanized, is reduced. Preferably, how- Th h t d t 0 5 X 8 h ever, the amount of carbon black in the rubber is from e S ee e S 06 was Into me h to 80 parts by weight of carbon black per 100 parts and Stacked to form two Strips each weighing aphroxb by weight of the elastomer in the compositions. mately l6.grams' The Sinps i freshemi'd (hglitly The use of sulphur as vulcanizing agent is preferred, washed) with n-hexane prior to being placed in a curing since this ingredient is known to be capable of facilitat- 25 mold' ing the bonding between the elastomeric composition The 9 w preheazed m a hdfaullc h and metals, and in particular, brass or zinc plated metpress mamtamed at 290 F for a mlmmum of 3 mmutes The mold was removed from the press, and loaded acals. The amount of sulphur in the synthetic rubber composition may be from 0.1 to 25 parts by weight, prefera- Colidmg to the fhnowmg sequhnce' brass plate y from 0.5 to 10 parts y weight p 100 parts y (8 inches X 0.5 inch 0.062 inch), rubber strip, brass Weight of the vulcanizable elastomer. plated steel wire sample, rubber strip, brass support Examples of accelerators useful in the invention are plate h top plate 2 mold The Sample was cured for mercaptobenzothiazole or N-cyclohexylbenzothiazole- 23 mmutes at 290 F under a r f of 23,000 z sulphenamide which y be present in an amount of, pounds. After the 23 minutes curing time, the mold was for example, from OJ to 6.0 parts by Weight per 100 removed from the press and the rubber sample containparts by weight of the elastomering both the support plates and wire was removed from The metals to which the elastomeric composition is the mcold and allowed to 9 to amblem temperature to be bonded include iron, steel, cobalt, nickel, copper, zinc, titanium, vanadium, chromium, tin and mixtures A h h h of the above Sample Preparahoh P of the above, more specifically brass and bronze. The 40 dure fhuhd m ASTM Test 132229-68- preferred metals of this invention are steel or brass, Teshhg Method bronze or zinc plated metals. It is not necessary for the After standlng at amblem temperature for 18 to 24 surface of the metal to be roughened before the comhohrsi the wh'es h Pulled f the rubber stofik position is applied Since the bond between the compo using an Instron Testing machine, in accordance with sition and the metal is not a mechanical one. However, the te stmg Procedm'e forth ASTM test 2229-68, it is preferred to free the metal surface of grease and the modificzftlons descl'lbed in Hicks, et dirt before the composition is applied al. in Rubber Chemistry and Technology, 45, 2648 The following examples, presented for illustration (1972)- and not limitation, will further serve to typify the na- ,g g i igs i reported below were obtained ac ture of the present Invention cording to the procedures described above. Pull-Out EXAMPLE 1 Force in the Table is the average force required to pull the wire from 0.5 inches of rubber. The blank value is Bonding of Natural Rubber to Brass Plated Steel Wire the average force required to p the wire from a for a. Preparation of Natural Rubber Stock mulation containing all of the ingredients except the on hun r P r Of natural fi were additive compound. All formulations with the same placed in a size B Banbury Mixer preheated to about stock designation number were prepared from the 1 10F and having a rotor speed of 116 rpm. After 0.5 same rubber stock.

TABLE I Addii iv dt ibinpdiind Pull-Out Force Stock Designation (lbs/0.5 in.)

TAB LE I Continued Adhesion of Nuturul Rubber to Brass Plated Steel Wire Pull-Out Furcu Addiliw Compound Stuck Designation MIN/0.5 in.)

Blank l MA T if Q 2 30.4

Blank 2 20.?

ll ll CNHNHC-@ 4 ii i Q-C-NHNH-CQ 1 42 OH HO i NHNH: 1

(CH;;)2 kt 1 3l N O O u A A n CNHNH N NHNHC OH HO Blank 29 HZUICIHO fi lO c NHNH.A 2.

OH H x 3 HO- CNHNH' OH 4 Blank 4 20 EXAMPLE 2 b. Sample Preparation Bonding of Styrene-Butadiene Copolymer to Brass Plated Steel Wire a. Preparation of Styrene-Butadiene Copolymer Stock 150 parts of a SBR Master-batch number 1605 (Ashland Chemical) containing 100.00 parts SBR and 50.00

parts carbon black FEF (N-SSO) were placed in a size B Banbury Mixer, initially heated to about F and having a rotor speed of 116 rpm. After mixing for 0.5 minutes, 2.82 parts of the zinz oxide and 0.71 parts of Age-Rite Resin D (antioxidant) were added and mixed for another minute. Stearic acid, 0.71 part, was then 5 The stock obtained after Banbury mixing was cut into smaller samples, ranging in size from 50 to grams. These were subsequently milled on a two roll mill at F for 7 minutes during which time 1.24 parts of sulfur, 0.64 part of Santocure NS, 0.14 parts of tetramethylthiuram monosulfide and either 1.00 part or 1.60 of the additive compound were added. After 7 minutes of milling, the stock was sheeted.

The sheeted stock was cut into 0.5 X 8.0 inch strips and stacked to form two strips each weighing approximately 16 grams. The strips were freshened (lightly washed) with n-hexane prior to being placed in the curing mold.

The mold was preheated in a hydraulic compression press maintained at 300F for a minimum of 3 minutes. The mold was removed from the press and loaded according to the following sequence: brass support plate (8 inch X 0.5 inch X 0.062 inch), rubber strip, brass plated steel wire samples, rubber strip, brass support plate and top plate of mold. The sample was cured for 24 minutes at 300F under a ram force of 23,000 pounds. After the 24 minutes curing time, themold was removed from the press and the rubber sample containing both the support plates and wires were removed from the mold and allowed to cool to ambient temperature (-72F).

A description of the above sample preparation procedure is found in ASTM Test D2229-68.

c. Test Method After standing at ambient temperature for 18 to 24 hours, the wires were pulled from the rubber stock using an Instron Testing machine according to ASTM Test 2229-68 but including the modifications described by A. E. Hicks, et a]. in Rubber Chemistry and Technology, 45, 26-48 (1972) d. Test Results The test results reported below were obtained according to the procedures described above. Pull-Out Force in the Table is the average force required to pull the wire from 0.5 inches of rubber. The blank value is the average force required to pull the wire from a formulation containing all of the ingredients except the additive compound. All formulations with the same stock designation number were prepared from the same rubber stock.

b. Sample Preparation The Banbury mixed stock was cut into smaller samples, ranging in-size from to 100 grams. These were milled on a two roll mill at 180F for 7 minutes during which time 1.50 parts of sulfur, 1.50 parts of tetramethylthiuram monosulfide, 0.50 part mercaptobenzothiazole and either 1.00 part or 1.60 parts of the additive compound were added. After 7 minutes of mill ing, the stock was sheeted.

the sheeted stock was cut into 0.5 X 8.0 inch strips and stacked to form two strips each weighing about 16 grams. The srips were freshened (lightly washed) with n-hexane prior to being placed in the curing mold.

The mold was preheated in a hydraulic compression press maintained at 300F for a minimum of 3 minutes. The mold was removed from the press and loaded according to the following sequence: brass support plate (8 inch X 0.5 inch X 0.062 inch), rubber strip, brass plated steel wire samples, rubber strip, brass support plate and top plate of mold. The sample was cured for 32 minutes at 300F under a ram force of 23,000 pounds. After the 32 minutes curing time, the mold was removed from the press and the rubber sample containing both the support plates and wires was removed from the mold and allowed to cool to ambient temperature (-72F).

A description of the above sample preparation proce- TABLE ll Adhesion of SBR to Brass Plutcd Steel Wire Additive Compound Concentration phr Stock Designation Pull-Out Force (lbs. /0.5 in.)

H O Q l l C=NNH l.()() I 33.9 OH Ho i? C=NNHC 1.60 1 42.6

OH H6 Blank I 16.6

0 ll ll 3 H -,C, NHNHC L00 3 34 Blank Z 17 EXAMPLE 3 dure is found in ASTM Test D2229-68.

Bonding of Ethylene-Propylene Terpolymer (EPDM) Rubber to Brass Plated Steel Wire a. Preparation of EPDM Rubber Stock The EPDM Rubber Stock was prepared by placing 100.00 parts of EPDM rubber (EPSYN 40A from Copolymer) in a size B Banbury Mixer preheated to about 120F and having a rotor speed of l 16 rpm. After mixing for 0.5 minute, 1.00 part of stearic acid was added and mixed for another 0.5 minute. One-half of 150.00 parts of cabon black FEF (N-550) was then added and mixed for an additional 0.5 minute. Then the remaining one-half of the carbon black, 5.00 parts of zinc oxide and 100.00 parts of process oil (Flexon 580) were added, the stock was mixed for another 4.5 minutes and then dumped. The total mixing time was 6 minutes and the dump temperature was about 335F.

c. Test Method After standing at ambient temperature for 18 to 24 hours, the wires were pulled from the rubber stock using an lnstron Testing machine according to ASTM Test 2229-68, but including the modifications described by A. E. Hicks et al in Rubber Chemistry and Technology, 45, 26-48 (1972).

d. Test Results 7 The test results reported below were obtained according to the procedures described above, Pull-Out Force in the Table is the average force required to pull the wire from 0.5 inches of rubber. The blank value is the average force required to pull the wire from a formulation containing all of the ingredients except the additive compound. All formulations with the same stock designation number were prepared from the same rubber stock TABLE Ill Adhesion of EPDM Rubber to Brass Plu'tcd Steel Wire Additive Compound Concentration ph r Stock Designation PUll-Out Force (lbs./().5 in.)

H O C J= J Q 1.00 I I6.()

\OH HO i ll (=N- r-u-|--c- L60 1 15.24 O Blank OH g l 3.2

M ii H ,-,C,, CNHNHC 1. 0 2 7 Blank 2 1 EXAMPLE 4 The mold was preheated in a hydraulic compression Bonding of Butyl Rubber to Brass Plated Steel Wire a. Preparation of Butyl Rubber Stock The Butyl Rubber stock was prepared by placing 100.00 parts of butyl rubber (ENJAY 365) and 100 part of stearic acid in a size B Banbury Mixer at room temperature (72F) and having a rotor speed of 155 rpm. After mixing for 0.5 minutes, one-half of 50.00 parts of carbon black FEF (N-550) was added and mixed for another 3 minutes. The remaining one-half of the carbon black, together with 5.00 parts of zinc oxide were added and then mixed for another 3 minutes. The mix was swept down, mixed for 2 more minutes and then dumped after a total mixing time of 8.5 minutes, at a temperature of about 340F.

b. Sample Preparation The Banbury mixed stock was cut into smaller samples, ranging in size from 50 to 100 grams. These were subsequently milled on a two roll mill at 150F for 8 minutes, during which time 0.50 parts of sulfur, either 1.00 part or 1.60 parts of the additive compound, and the accelerator system consisting of 3.00 parts Ethyl Tellurac and 1.00 parts MBT (Thiofide) were added. After 8 minutes of milling, the stock was sheeted.

The sheeted stock was cut into 0.5 X 8.0 inch strips and stacked to form two strips each weighing about 16 grams. The strips were freshened (lightly washed) with n-hexane prior to being placed in the curing mold.

press maintained at 316F for a minimum of 3 minutes. The mold was removed from the press and loaded according to the following sequence: brass support plate (8 inches X 0.5 inches X 0.062 inches), rubber strip, wiere samples, rubber strip, brass support plate and top plate of mold. The sample was cured for 22 minutes at 316F under a ram force of 23,000 pounds. After the 22 minutes curing time, the mold was removed from the press and the rubber sample containing both the support plates and wires was removed from the mold and allowed to cool to ambient temperature (72F).

A description of the above sample preparation procedure is found in ASTM Test D2229-68.

c. Testing Method After standing at ambient temperature for 18 to 24 hours, the wires were pulled from the rubber stock using an Instron Testing machine according to ASTM Test 2229-68, including the modifications described by A. E. Hicks et al. in Rubber Chemistry and Technology, 45, 26-48 (1972) d. Test Results The test results reported below were obtained according to the procedures described above. Pull-Out Force in the Table is the average force required to pull the wire from 0.5 inches of rubber. The blank value is the average force required to pull the wire from a formulation containing all of the ingredients except the additive compound. All formulations with the same stock designation number were prepared from the same rubber stock.

TABLE IV Adhesion of Butyl Rubber to Brass Plated Steel Wire Additive Compound Concentration phr Stock Designation PulLOut Force (lbs./0.5 in.)

'i ii Q Z@ 1.00 I 10.2:

OH H

H ll Qslzmmp 1.6.. 1 11.8

OH H

Blank What is claimed is:

1. A method of improving adhesion between a vulcanizable elastomeric composition and a metal surface to provide a strong and durable bond, which method comprises a. adding to a vulcanizable elastomeric composition from 0.05 phr to phr by weight based on the weight of the elastomer of an organic hydrazine derivative with metal deactivating efficiency, and

b. vulcanizing the composition while it is in contact with the metal surface.

2. The method of claim 1 wherein the vulcanizable elastomer is selected from natural rubber, styrenebutadiene copolymer, ethylene-propylene terpolymer or butyl rubber containing at least 0.8% unsaturation.

3. The method of claim 1 wherein the organic hydrazine derivative is present in an amount of from 0.1 to

5.0 phr by weight, based onthe weight of the elastomer.

4. The method of claim 1 wherein the elastomeric composition contains carbon black.

5. The method of claim 1 wherein the vulcanizing agent is sulfur.

6. The method of claim 1 wherein the vulcanizable elastomer is natural rubber and the organic hydrazine 

1. A METHOD OF IMPROVING ADHESION BETWEEN A VULCANIZABLE ELASTOMERIC COMPOSITION AND A METAL SURFACE TO PROVIDE A STRONG AND DURABLE BOND, WHICH METHOD COMPRISES A. ADDING TO A VULCANIZABLE ELASTOMERIC COMPOSITION FROM 0.05 PHR TO 10 BY WEIGHT BASED ON THE WEIGHT OF THE ELASTOMER OF AN ORGANIC HYDROZINE DERIVATIVE WITH METAL DEACTING EFFICIENCY, AND B. VULCANIZING THE COMPOSITION WHILE IT IS IN CONDUCT WITH THE METAL SURFACE.
 2. The method of claim 1 wherein the vulcanizable elastomer is selected from natural rubber, styrene-butadiene copolymer, ethylene-propylene terpolymer or butyl rubber containing at least 0.8% unsaturation.
 3. The method of claim 1 wherein the organic hydrazine derivative is present in an amount of from 0.1 to 5.0 phr by weight, based on the weight of the elastomer.
 4. The method of claim 1 wherein the elastomeric composition contains carbon black.
 5. The method of claim 1 wherein the vulcanizing agent is sulfur.
 6. The method of claim 1 wherein the vulcanizable elastomer is natural rubber and the organic hydrazine derivative has the formula
 7. The method of claim 6 wherein the organic hydrazine derivative is oxalo-bis-(2-hydroxy-benzylidene-hydrazide). 